Its sensor (detector) senses the gas concentration and transmits a proportionate signal to the digital monitor. Modern integrated circuits provide all needed indication, alarm, and fail safe functions with simplicity of installation and operation. Monitor is built into a protective rigid Aluminum case. A window on the front face allows visibility of digital LCD indicator. LED alarm lights are provided on the left side of digital meter for individual gases, and below the meter is the manual push button switches for reset and for various functions as explained below separately. The electronic components and integrated circuits are mounted on a single printed circuit board.